In the field of combustion engines, it is well known that fuels such as gasoline, diesel, and ethanol are used in a combustion process to power engines. However, it is also well known that the use of such fuels generates byproducts which are harmful to the environment. Further, aside from environmental concerns, the use of such fuels is costly to the consumer.
In view of these concerns, it is desirable to at least substantially reduce, if not eliminate, the use of combustible fuels. One source of power is compressed air, or pneumatics. Several devices have been developed for using pneumatic power to operate engines. Pneumatically powered engines and devices to convert engines to pneumatic or other pressurized fluid power are known in the art, but they have not been well received by industry for several reasons.
One reason is that some of these inventions depend upon a new engine block, a very expensive and impractical idea.
Another reason is that many of these devices do not adequately address leakage problems, and engine efficiency is compromised.
Yet another reason is that several of these inventions do not eliminate the compression stroke, a severe restriction to engine operation which could only be overcome by providing extremely high pressures. But this is impractical since most compressors are designed to produce less than 200 p.s.i., 125 p.s.i. is most common.
Another reason is that several of these inventions include recirculating or recycling devices, again a significant resistant force against efficient engine operation and unnecessary in the case of compressed air since it is non-polluting.
Still another reason is that some of these inventions include somewhat complicated devices or even numerous devices for distributing and/or delivering compressed air or pressurized fluid to the cylinders.
Typical of the art are those devices disclosed in the following United States Letters Patents:
______________________________________ U.S. Pat. No. Patentee Issue Date ______________________________________ 3,885,387 Simington May 27, 1975 3,925,984 Holleyman Dec 16, 1975 4,018,050 Murphy Apr 19, 1977 4,102,130 Stricklin Jul 25, 1978 4,162,614 Holleyman Jul 31, 1979 4,292,804 Rogers, Sr. Oct 6, 1981 4,596,119 Johnson Jun 24, 1986 4,896,505 Holleyman Jan 30, 1990 5,163,292 Holleyman Nov 17, 1992 ______________________________________
Simington ('387) shows an air drive adaptor consisting of a valving means for introducing compressed air to engine cylinders, however no means of eliminating the compression stroke is shown. Atmospheric air is admitted via intake valve on intake stroke, compressed during compression stroke, supplemented by compressed air via valving means for power stroke, then exhausted to atmosphere on exhaust stroke.
U.S. Pat. No. 3925984 is a compressed air power plant which uses manifold means and solenoid operated valves to deliver compressed air to cylinders. Discharged air is received in an exhaust tank and is then pumped into a high-pressure tank. This invention does not claim a means of converting a four-stroke internal combustion engine to a two-stroke engine operated by compressed air.
Murphy ('050) teaches a compressed air operated motor employing dual lobe cams using a modified camshaft to operate both intake and exhaust valves of the motor. Compressed air must be continuously supplied to the intake manifold. The large perimeter of the intake manifold must be adequately sealed to contain the compressed air. Exhausted air is recompressed. Murphy does not use a distributor. As described, this invention may require a new intake manifold, an economical disadvantage.
The invention by Stricklin ('130) converts a four-stroke internal combustion engine into a two-stroke engine powered by steam or compressed air by changing the relation of the camming action either by replacing the camshaft gear to one the same size as the crankshaft gear or by modifying the camshaft lobes to being dual-lobed. He does not use a distributor but uses the intake valves and intake ports to introduce steam or compressed air from the manifold to the cylinders. Sealing the large perimeter of the intake manifold to contain the pressure may be a significant problem. This invention includes a means of reversing the direction of the engine operation so that the transmission and/or clutch can be removed.
U.S. Pat. No. 4162614 is a pressure fluid operated power plant that includes a distributor which simply splits the main supply line into a plurality of supply lines, one for each cylinder of the engine, an actuating valve for each individual supply line, and a unitary inlet and exhaust valve, or spool valve, for each cylinder to control the intake and exhaust of pressure fluid. As shown, the engine is not a converted four-stroke internal combustion engine, but a different engine with the crankshaft configured so that the pistons do not operate in pairs and without the standard engine valves. Also, fluid exhaust goes into a tank to be recycled for re-use or for use elsewhere.
Rogers, Sr. ('804) shows electrically operated valve actuating means to control the intake of compressed gas to the cylinders. He also provides for recycling at least a portion of the gas exhausted to be recompressed or to cool transmission fluid or to be used as a working fluid in an air conditioning system. The valve actuator operates only one valve at a time and therefore only one cylinder receives compressed gas. Applied to a typical engine, the compression stroke is not eliminated. No provision is made to convert the engine to a two-stroke operation. This invention also uses altering means for increasing the duration of each engine cycle over which the valve means admits compressed gas to the at least one cylinder as the speed of the engine increases. However, compressed gas must be supplied during the entire power stroke, regardless of the speed of the engine.
Johnson ('119) teaches a compressed air propulsion system for a vehicle which includes an air distributor system comprising a plurality of solenoids and electrically operated microswitches to operate air supply intake valves. Johnson does not show a means of eliminating the compression stroke, that is, he is not converting a four-stroke engine to two-stroke operation.
U.S. Pat. No. 4896505 is a pressurized fluid operated engine that includes a rotary type distributor which supplies pressurized fluid to the engine cylinders via spool valves which control both intake and exhaust. This invention includes a recirculation means for recycling at least a portion of exhaust gas. Holleyman attempts to address the resulting resistance to engine operation by describing ejector means. The rotary distributor means as described and shown would present problems relating to leakage to other than the desired supply line and if tightly assembled to reduce leakage, friction would be created, and therefore heat and resistance. As with his earlier patents, Holleyman is not converting a typical four-stroke engine to a two-stroke operation for pressurized fluid. He does not show the standard configuration of the crankshaft whereby pistons move in pairs and does not show the engine's intake and exhaust valves.
U.S. Pat. No. 5163292 shows the rotary distributor of Holleyman's previous patent has been modified to lengthen the amount of time that pressurized fluid is permitted through each supply line to a cylinder via a pressure sensitive snap action diaphragm valve. However there has been no modification made to the rotary distributor to address the problem of pressurized fluid leakage to undesired supply lines. The diaphragm valves replace the former spool valves for controlling intake and exhaust of pressurized fluid. Exhaust pressure must exceed inlet pressure for valves to operate on the exhaust stroke and this could cause some resistance. Holleyman also includes a fluid mixing means used to recycle spent fuel. Like his previous patents, Holleyman does not claim to be converting a combustion engine to a two-stroke operation to use pressurized fluid.
In view of the prior art, it is the main object of this invention to provide an improved apparatus to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine which minimizes the aforementioned problems, that is, leakage and resistant forces are eliminated thereby achieving the maximum efficiency and performance of the engine.
It is another object of this invention to provide an apparatus to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine in order to preserve natural resources.
It is a further object of the present invention to provide an improved pneumatic distributor for mounting on an existing timing mechanism of an engine, the pneumatic distributor operating in similar fashion to conventional electrical distributors while eliminating the need for electrical current thereto.
Another object of the present invention is to provide an apparatus to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine while retaining a substantial portion of the existing parts of the engine, thereby minimizing the costs involved in such conversion.
Still another object of this invention is to provide an apparatus to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine such that air and noise pollution created by the operation of the engine is substantially reduced.
Yet another object of the present invention is to provide such an apparatus to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine whereby the cost of operation of the engine is substantially reduced.
Other objects and advantages will be accomplished by the present invention which serves to replace combustible fuel systems associated with the operation of an engine. Thus, the present invention is designed to preserve natural resources which are rapidly being depleted.